The terminologies of transient, migratory, or localized osteoporosis, and bone marrow edema syndrome: a scoping review

There is no formally defined terminology for the related entities transient osteoporosis of the hip (TOH), localized or regional migratory osteoporosis (RMO) and bone marrow edema syndrome (BMES). This study aimed to map the diversity and frequency of diagnostic terms and vocabulary utilized in the literature. A comprehensive search of electronic databases and reference lists was conducted. Publications that reported on patients with TOH, RMO, BMES, or related variants were eligible for inclusion. The terminologies were categorized based on the wording of the titles, abstracts, or texts. We included 561 publications, of which 423 were case reports, involving 2921 patients. Overall, TOH was the most commonly used term, occurring in 257 (45.8%). RMO was used in 34 (6.1%) and BMES in 57 (10.2%). The remaining used various combinations of transient, migratory, and regional in conjunction with either osteoporosis or bone marrow edema. Localized osteoporosis was not used. We identified three different terms related to pregnancy. In 76.3% of the publications, the terminology was related to osteoporosis and in 18.2% to bone marrow edema, although terminology did not correspond to actual findings. Bone marrow edema occurred as often as osteoporosis, and osteoporosis was generally ascertained by visual inspection of radiographs, seldom by bone densitometry. Many publications used osteoporosis-related terms without evidence that osteoporosis had been detected. The terminology of these closely related entities is confusing and unstandardized. The lack of formal definitions impedes accurate diagnosis, research on disease mechanisms, and effective treatment.

Longitudinal Relationship Between Reduced Modic Change Edema and Disability and Pain in Patients With Chronic Low Back Pain

STUDY DESIGN

Secondary analyses of a randomized trial [Antibiotics In Modic changes (MCs) study].

OBJECTIVE

To assess whether or not reduced MC edema over time is related to reduced disability and pain in patients with chronic low back pain (LBP).

SUMMARY OF BACKGROUND DATA

It is not clear whether or not reduced MC edema implies improved clinical outcomes.

PATIENTS AND METHODS

Linear regression was conducted separately in 2 subgroups with MC edema at baseline on short tau inversion recovery (STIR) or T1/T2-weighted magnetic resonance imaging, respectively. Independent variable: reduced edema (yes/no) at 1 year on STIR or T1/T2-series, respectively. Dependent variable: 1-year score on the Roland-Morris Disability Questionnaire (RMDQ), Oswestry Disability Index (ODI), or 0 to 10 numeric rating scale for LBP intensity, adjusted for the baseline score, age, smoking, body mass index, physical workload, and baseline edema on STIR (STIR analysis only). Post hoc, we, in addition, adjusted all analyses for baseline edema on STIR, treatment group (amoxicillin/placebo), and prior disc surgery-or for disc degeneration.

RESULTS

Among patients with MC edema on STIR at baseline (n = 162), reduced edema on STIR was not significantly related to the RMDQ ( B : -1.0, 95% CI: -2.8, 0.8; P = 0.27), ODI ( B :-1.4, 95% CI: -5.4, 2.6; P = 0.50), or LBP intensity scores ( B : -0.05, 95% CI: -0.8, 0.7; P = 0.90) after 1 year. Among patients with MC edema on T1/T2-series at baseline (n = 116), reduced edema on T1/T2 ( i.e ., reduced volume of the type 1 part of MCs) was not significantly related to RMDQ ( B: -1.7, 95% CI: -3.8, 0.3; P = 0.10) or ODI score ( B : -2.3, 95% CI: -7.1, 2.5; P = 0.34) but was significantly related to LBP intensity at 1 year ( B : -0.9, 95% CI: -1.8, -0.04; P = 0.04; correlation coefficient: 0.24). The post hoc analyses supported these results.

CONCLUSION

Reduced MC edema over 1 year was not significantly associated with pain-related disability but was (on T1/T2-series) significantly but weakly related to reduced LBP intensity.

LEVEL OF EVIDENCE

Level 3.

Cytokine Patterns as Predictors of Antibiotic Treatment Effect in Chronic Low Back Pain with Modic Changes: Subgroup Analyses of a Randomized Trial (AIM Study)

Objective

Randomized trials testing the effect of antibiotics for chronic low back pain (LBP) with vertebral bone marrow changes on MRI (Modic changes) report inconsistent results. A proposed explanation is subgroups with low grade discitis where antibiotics are effective, but there is currently no method to identify such subgroups. The objective of the present study was to evaluate whether distinct patterns of serum cytokine levels predict any treatment effect of oral amoxicillin at one-year follow-up in patients with chronic low back pain and Modic changes at the level of a previous lumbar disc herniation.

Design

We used data from an overpowered, randomized, placebo-controlled trial (the AIM study) that tested 100 days of oral 750 mg amoxicillin vs placebo three times daily in hospital outpatients with chronic (>6 months) LBP with pain intensity ≥5 on a 0-10 numerical rating scale and Modic changes type 1 (oedema type) or 2 (fatty type). We measured serum levels of 40 inflammatory cytokines at baseline and analysed six predefined potential predictors of treatment effect based on cytokine patterns in 78 randomized patients; three analyses with recursive partitioning, one based on cluster analysis and two based on principal component analyses. The primary outcome was the Roland-Morris Disability Questionnaire score at one-year follow-up in the intention to treat population. The methodology and overall results of the AIM study were published previously.

Results

The 78 patients were 25-62 years old and 47 (60%) were women. None of the three recursive partitioning analyses resulted in any suggested subgroups. Of all main analyses, the largest effect estimate (mean difference between antibiotic and placebo groups) was seen in a subgroup not predefined as of main interest (Cluster category 3+4; -2.0, 95% CI: -5.2-1.3, RMDQ points; p-value for interaction 0.54).

Conclusion

Patterns of inflammatory serum cytokine levels did not predict treatment effect of amoxicillin in patients with chronic LBP and Modic changes.

Clinical Trial Registration Number

ClinicalTrials.gov (identifier: NCT02323412).

Symptom descriptors and patterns in lumbar radicular pain caused by disc herniation: a 1-year longitudinal cohort study

OBJECTIVE

The objective of the present study was to explore the diversity, quality, severity and distribution of symptoms in patients with radicular pain and a lumbar disc herniation.

DESIGN

Longitudinal cohort study.

SETTING

Hospital-based back clinic.

PARTICIPANTS

Ninety patients referred to secondary healthcare with (a) low back-related leg pain, (b) age between 18 and 65 years and (c) MRI confirmed lumbar disc herniation at a relevant side and level.

OUTCOME MEASURES

Neuropathic pain symptoms were assessed using the Short-Form McGill Pain Questionnaire-2 (SF-MPQ-2) and the painDETECT Questionnaire. In a subsample classified with neuropathic pain, in-depth interviews were performed, and symptomatic areas were drawn on standardised body charts.

RESULTS

At baseline, the most frequently used painDETECT symptom descriptor was numbness sensation, reported by 94%, followed by sudden pain attacks and tingling or prickling. The mean (SD) SF-MPQ-2 score (0-10) for aching pain was 5.9 (2.8); numbness 4.3 (3.3); tingling 4.0 (3.4); burning 2.6 (3.1); pain caused by light touch 1.5 (2.6). Leg pain was rated as extremely bothersome by 73%, numbness and tingling by 38%, weakness by 24% and back pain by 17%. In the subsample (n=52), deep-lying pain and non-painful abnormal sensations were frequent, at 71% and 85%. Drawings demonstrated substantial overlap between symptoms from compromised L5 and the S1 nerve roots. Painful and non-painful symptoms improved at approximately the same rate. At the 1-year follow-up, 45% (14/31) of patients who had received disc surgery, and 34% (18/53) of those who had received conservative treatment reported no bothersome back pain, leg pain, numbness/tingling or weakness.

CONCLUSION

Patients reported several highly bothersome symptoms, but not all are described as painful. The overall symptom profile of lumbar disc-related radicular pain differs from other neuropathic pain conditions with limited allodynia and thermal hyperalgesia. Symptomatic areas for the L5 and S1 nerve roots have a large overlap.

Apparent diffusion coefficient values in Modic changes – interobserver reproducibility and relation to Modic type

Background

Modic Changes (MCs) in the vertebral bone marrow were related to back pain in some studies but have uncertain clinical relevance. Diffusion weighted MRI with apparent diffusion coefficient (ADC)-measurements can add information on bone marrow lesions. However, few have studied ADC measurements in MCs. Further studies require reproducible and valid measurements. We expect valid ADC values to be higher in MC type 1 (oedema type) vs type 3 (sclerotic type) vs type 2 (fatty type). Accordingly, the purpose of this study was to evaluate ADC values in MCs for interobserver reproducibility and relation to MC type.

Methods

We used ADC maps (b 50, 400, 800 s/mm²) from 1.5 T lumbar spine MRI of 90 chronic low back pain patients with MCs in the AIM (Antibiotics In Modic changes)-study. Two radiologists independently measured ADC in fixed-sized regions of interests. Variables were MC-ADC (ADC in MC), MC-ADC% (0% = vertebral body, 100% = cerebrospinal fluid) and MC-ADC-ratio (MC-ADC divided by vertebral body ADC). We calculated mean difference between observers ± limits of agreement (LoA) at separate endplates. The relation between ADC variables and MC type was assessed using linear mixed-effects models and by calculating the area under the receiver operating characteristic curve (AUC).

Results

The 90 patients (mean age 44 years; 54 women) had 224 MCs Th12-S1 comprising type 1 (n = 111), type 2 (n = 91) and type 3 MC groups (n = 22). All ADC variables had higher predicted mean for type 1 vs 3 vs 2 (p < 0.001 to 0.02): MC-ADC (10^− 6 mm²/s) 1201/796/576, MC-ADC% 36/21/14, and MC-ADC-ratio 5.9/4.2/3.1. MC-ADC and MC-ADC% had moderate to high ability to discriminate between the MC type groups (AUC 0.73–0.91). MC-ADC-ratio had low to moderate ability (AUC 0.67–0.85). At L4-S1, widest/narrowest LoA were for MC-ADC 20 ± 407/12 ± 254, MC-ADC% 1.6 ± 18.8/1.4 ± 10.4, and MC-ADC-ratio 0.3 ± 4.3/0.2 ± 3.9. Difference between observers > 50% of their mean value was less frequent for MC-ADC (9% of MCs) vs MC-ADC% and MC-ADC-ratio (17–20%).

Conclusions

The MC-ADC variable (highest mean ADC in the MC) had best interobserver reproducibility, discriminated between MC type groups, and may be used in further research. ADC values differed between MC types as expected from previously reported MC histology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05610-4.

Minimal important change was on the lower spectrum of previous estimates and responsiveness was sufficient for core outcomes in chronic low back pain

OBJECTIVES

The objective of this study was to estimate the minimal important change (MIC) and responsiveness of core patient reported outcome measures for chronic low back pain (LBP) and Modic changes.

STUDY DESIGN AND SETTING

In the Antibiotics in Modic changes (AIM) trial we measured disability (RMDQ, ODI), LBP intensity (NRS) and health-related quality of life (EQ5D) electronically at baseline, three- and 12-month follow-up. MICs were estimated using Receiver Operating Curve (ROC) curve and Predictive modeling analyses against the global perceived effect. Credibility of the estimates was assessed by a standardized set of criteria. Responsiveness was assessed by a construct and criterion approach according to COSMIN guidelines.

RESULTS

The MIC estimates of RMDQ, ODI and NRS scores varied between a 15-40% reduction, depending on including "slightly improved" in the definition of MIC or not. The MIC estimates for EQ5D were lower. The credibility of the estimates was moderate. For responsiveness, five out of six hypotheses were confirmed and AUC was >0.7 for all PROMs.

CONCLUSION

When evaluated in a clinical trial of patients with chronic LBP and Modic changes, MIC thresholds for all PROMs were on the lower spectrum of previous estimates, varying depending on the definition of MIC. Responsiveness was sufficient.

Strategies to manage auxiliary pain medications in chronic pain trials: a topical review

Chronic pain trials commonly allow auxiliary pain medications such as rescue and concomitant analgesics in addition to the randomized treatment. Changes in auxiliary pain medications after randomization represent intercurrent events that may affect either the interpretation or the existence of the measurements associated with the clinical question of interest, complicating the assessment of treatment efficacy. In chronic pain trials, pain intensity typically varies and patients may take the auxiliary medications 1 day but not the next or increase and decrease the dosages temporarily while continuing their randomized study medication. This distinctive feature of auxiliary pain medications as an intercurrent event has received little attention in the literature. Further clarifications on how to manage these issues are therefore pressing. Here we provide perspectives on issues related to auxiliary pain medication-related intercurrent events in randomized controlled chronic pain trials considering the strategies suggested in the E9(R1) addendum to the ICH guideline on statistical principles for clinical trials.

NSAIDs in sciatica (NIS): study protocol for an investigator-initiated multicentre, randomized placebo-controlled trial of naproxen in patients with sciatica

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used to treat sciatica, despite insufficient evidence from placebo-controlled trials. NSAIDs may cause serious side effects; hence, there is a strong need to clarify their potential beneficial effects in patients with sciatica.

METHODS

This is a multicentre, randomized, placebo-controlled, parallel-group superiority trial. Participants will be recruited among sciatica patients referred to outpatient clinics at hospitals in Norway who have radiating pain below the knee with a severity score of ≥ 4 on a 0-10 numeric rating scale and clinical signs of nerve root or spinal nerve involvement. The intervention consists of oral naproxen 500 mg or placebo twice daily for 10 days. Participants will report the outcomes and adverse events daily using an electronic case report form. The primary endpoint is change in leg pain intensity from baseline to day 10 based on daily observations. The secondary outcomes are back pain intensity, disability, sciatica symptom severity, rescue medication (paracetamol) consumption, opioid use, ability to work or study, 30% and 50% improvement in leg pain, and global perceived change of sciatica/back problem. The outcomes will be analysed using mixed effects models for repeated measurements. The total duration of follow-up is 12 (± 2) days.

DISCUSSION

This trial aims to evaluate the benefits of naproxen, a non-selective NSAID, in patients with sciatica. No important differences in efficacy have been demonstrated between different NSAIDs in the management of musculoskeletal disorders; hence, the results of this trial will likely be applicable to other NSAIDs.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03347929 . Registered on November 20, 2017.

Impact of rescue medication in placebo-controlled trials of pharmacotherapy for neuropathic pain and low back pain

ABSTRACT

Rescue medication (RM) consumption is commonly used as a secondary outcome in placebo-controlled trials of chronic pain, but its validity has yet to be established. If participants randomized to placebo take more RM than those randomized to an active drug, the difference in pain between the 2 groups may be reduced, potentially masking effects of the active drug. This study assessed proportional RM consumption in the placebo and active groups according to results of 42 randomized controlled trials of neuropathic pain (NeP), and 29 trials of low back pain, which were included in 2 systematic reviews and meta-analyses. Trial results were assessed based on effect size, statistical significance, and whether the drug was recommended as first-line treatment by the systematic reviews. In trials indicating effect of the investigational drug, RM consumption was generally higher in the placebo groups than in the active groups. In trials reporting a small or a medium effect size of the investigational drug, subjects receiving placebo consumed 17% to 30% more RM than subjects receiving active drug, potentially leading to underestimation of the effects of the investigational drugs. Few trials reported a large effect size. Differences in RM consumption between participants receiving placebo and those receiving active drug were seldom taken in account by the individual trials and not at all by the systemic reviews when making treatment recommendations for NeP or low back pain. Elaboration on analytical methods to assess treatment effects in chronic pain trials using RM is warranted.

Pinprick and Light Touch Are Adequate to Establish Sensory Dysfunction in Patients with Lumbar Radicular Pain and Disc Herniation

BACKGROUND

The frequency with which sensory disturbances occur in patients with radicular leg pain and disc herniation is not well known, and the efficacy of tests to identify such changes are not firmly established. The presence of sensory disturbances is a key sign of nerve root involvement and may contribute to the diagnosis of a lumbar disc herniation, identify patients for referral to spinal imaging and surgery, and improve disease classification.

QUESTIONS/PURPOSES

In this study, we sought: (1) to determine the frequency with which abnormal sensory findings occur in patients with lumbar disc herniation-related radicular pain, using a standard neurological sensory examination; (2) to determine what particular standard sensory test or combination of tests is most effective in establishing sensory dysfunction; and (3) to determine whether a more detailed in-depth sensory examination results in more patients being identified as having abnormal sensory findings.

METHODS

Between October 2013 and April 2016, 115 patients aged 18 to 65 years referred to secondary health care with radicular leg pain and disc herniation were considered potentially eligible for inclusion in the study. Based on these inclusion criteria, 79% (91) were found eligible. Ten percent (11) were excluded because of other illness that interfered with the study purpose, 3% (3) because of cauda equina syndrome, 2% (2) because of spinal stenosis, 2% (2) because of prior surgery at the same disc level, and 2% (2) because of poor Norwegian language skills. Three percent (4) of the patients did not want to participate in the study. Of the 91 eligible patients, 56% (51) consented to undergo a comprehensive clinical examination and were used for analysis here. The sample for the purposes of the present study was predetermined at 50. These patients were first examined by a standard procedure, including sensory assessment of light touch, pinprick, vibration, and warmth and cold over the back and legs. Second, an in-depth semiquantitative sensory testing procedure was performed in the main pain area to assess sensory dysfunction and improve the detection of potential positive sensory signs, or sensory gain of function more precisely. Sensory loss was defined as sensations experienced as distinctly reduced in the painful side compared with the contralateral reference side. In contrast, sensory gain was defined as sensations experienced as abnormally strong, unpleasant, or painful and distinctly stronger than the contralateral side. Ambiguous test results were coded as a normal response to avoid inflating the findings. The proportions of abnormal findings were calculated for each sensory modality and for all combinations of the standard examination tests.

RESULTS

The standard examination identified at least one abnormal finding in 88% (45 of 51) of patients. Sensory loss was present in 80% (41), while sensory gain was present in 35% (18). The combination of pinprick and light touch identified all patients who were classified as having abnormal findings by the full standard examination. The semiquantitative procedure identified an additional three patients with an abnormal finding.

CONCLUSION

We suggest that the combination of pinprick and light touch assessment is an adequate minimal approach for diagnostic and classification purposes in patients with lumbar radicular pain.

LEVEL OF EVIDENCE

Level I, diagnostic study.

Oedema on STIR modified the effect of amoxicillin as treatment for chronic low back pain with Modic changes-subgroup analysis of a randomized trial

Objective

To evaluate potential MRI-defined effect modifiers of amoxicillin treatment in patients with chronic low back pain and type 1 or 2 Modic changes (MCs) at the level of a previous lumbar disc herniation (index level).

Methods

In a prospective trial (AIM), 180 patients (25–64 years; mean age 45; 105 women) were randomised to receive amoxicillin or placebo for 3 months. Primary outcome was the Roland-Morris Disability Questionnaire (RMDQ) score (0–24 scale) at 1 year. Mean RMDQ score difference between the groups at 1 year defined the treatment effect; 4 RMDQ points defined the minimal clinically important effect. Predefined baseline MRI features of MCs at the index level(s) were investigated as potential effect modifiers. The predefined primary hypothesis was a better effect of amoxicillin when short tau inversion recovery (STIR) shows more MC-related high signal. To evaluate this hypothesis, we pre-constructed a composite variable with three categories (STIR1/2/3). STIR3 implied MC-related STIR signal increases with volume ≥ 25% and height > 50% of vertebral body and maximum intensity increase ≥ 25% and presence on both sides of the disc. As pre-planned, interaction with treatment was analysed using ANCOVA in the per protocol population (n = 155).

Results

The STIR3 composite group (n = 41) and STIR signal volume ≥ 25% alone (n = 45) modified the treatment effect of amoxicillin. As hypothesised, STIR3 patients reported the largest effect (− 5.1 RMDQ points; 95% CI − 8.2 to − 1.9; p for interaction = 0.008).

Conclusions

Predefined subgroups with abundant MC-related index-level oedema on STIR modified the effect of amoxicillin. This finding needs replication and further support.

Key Points

• In the primary analysis of the AIM trial, the effect of amoxicillin in patients with chronic low back pain and type 1 or 2 MCs did not reach the predefined cut-off for clinical importance.

• In the present MRI subgroup analysis of AIM, predefined subgroups with abundant MC-related oedema on STIR reported an effect of amoxicillin.

• This finding requires replication and further support.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-020-07542-w.

The effect of infliximab in patients with chronic low back pain and Modic changes (the BackToBasic study): study protocol of a randomized, double blind, placebo-controlled, multicenter trial

BACKGROUND

Low back pain is common and a significant number of patients experience chronic low back pain. Current treatment options offer small to moderate effects. Patients with vertebral bone marrow lesions visualized as Modic changes on magnetic resonance imaging may represent a subgroup within the low back pain population. There is evidence for inflammatory mediators being involved in development of Modic changes; hence, suppression of inflammation could be a treatment strategy for these patients. This study examines the effect of anti-inflammatory treatment with the TNF-α inhibitor infliximab in patients with chronic low back pain and Modic changes.

METHODS/DESIGN

The BackToBasic trial is a multicenter, double blind, randomized controlled trial conducted at six hospitals in Norway, comparing intravenous infusions with infliximab with placebo. One hundred twenty-six patients aged 18-65 with chronic low back pain and type 1 Modic changes will be recruited from secondary care outpatients' clinics. The primary outcome is back pain-specific disability at day 154 (5 months). The study is designed to detect a difference in change of 10 (SD 18) in the Oswestry Disability Index at day 154/ 5 months. The study also aims to refine MRI-assessment, investigate safety and cost-effectiveness and explore the underlying biological mechanisms of Modic changes.

DISCUSSION

Finding treatments that target underlying mechanisms could pose new treatment options for patients with low back pain. Suppression of inflammation could be a treatment strategy for patients with low back pain and Modic changes. This paper presents the design of the BackToBasic study, where we will assess the effect of an anti-inflammatory treatment versus placebo in patients with chronic low back pain and type 1 Modic changes. The study is registered at ClinicalTrials.gov under the identifier NCT03704363 . The EudraCT Number: 2017-004861-29.

Clinical effect modifiers of antibiotic treatment in patients with chronic low back pain and Modic changes - secondary analyses of a randomised, placebo-controlled trial (the AIM study)

Background

Randomised trials on antibiotic treatment for patients with chronic low back pain and vertebral endplate changes visible on MRI (Modic changes) have shown mixed results. A possible explanation might be a real treatment effect in subgroups of the study populations. The purpose of the present study was to explore potential clinical effect modifiers of 3-months oral amoxicillin treatment in patients with chronic low back pain and type I or II Modic changes at the level of a previous lumbar disc herniation.

Methods

We performed analyses of effect modifiers on data from AIM, a double-blind parallel-group multicentre trial. One hundred eighty patients with chronic low back pain, previous disc herniation, Modic change type I (n = 118) or type II (n = 62) were randomised to 3-months oral treatment with 750 mg amoxicillin (n = 89) or placebo (n = 91) three times daily. The primary outcome was the Roland-Morris Disability Questionnaire (RMDQ) score (possible values 0–24) at 1-year follow-up in the intention-to-treat population. The predefined minimal clinically important between-group mean difference was 4 RMDQ points (not reached in the primary analysis of AIM). Predefined baseline characteristics were analysed as potential effect modifiers, four primary (type I Modic changes, previous disc surgery, positive pain provocation test, high CRP) and five exploratory (disturbed sleep, constant low back pain, short duration of low back pain, younger age, and male) using ANCOVA with interaction terms.

Results

None of the four primary potential effect modifiers had strong evidence of modifying the treatment effect. In patients younger than 40 years the difference in mean RMDQ score between the treatment groups was − 4.0 (95%CI, − 6.9 to − 1.2), compared to − 0.5 (95%CI, − 2.3 to 1.3) in patients 40 years or older, both in favour of amoxicillin treatment (exploratory analysis).

Conclusions

We did not find evidence for convincing clinical effect modifiers of antibiotic treatment in patients with chronic low back pain and Modic changes. Our results for younger age in these explorative analyses should not affect clinical treatment decisions without confirmation in future studies.

Trial registration

ClinicalTrials.gov NCT02323412, First registered 23 December 2014.

Cost-utility analysis of antibiotic treatment in patients with chronic low back pain and Modic changes: results from a randomised, placebo-controlled trial in Norway (the AIM study)

OBJECTIVE

To evaluate the cost-utility of 100 days of antibiotics in patients with chronic low back pain (LBP) and type I or II Modic changes included in the Antibiotic treatment In patients with chronic low back pain and Modic changes (AIM) study.

DESIGN

A cost-utility analysis from a societal and healthcare perspective alongside a double-blinded, parallel group, placebo, multicentre trial.

SETTING

Hospital outpatient clinics at six hospitals in Norway. The main results from the AIM study showed a small effect in back-related disability in favour of the antibiotics group, and slightly larger in those with type I Modic changes, but this effect was below the pre-defined threshold for clinically relevant effect.

PARTICIPANTS

180 patients with chronic LBP, previous disc herniation and Modic changes type I (n=118) or type II (n=62) were randomised to antibiotic treatment (n=89) or placebo-control (n=91).

INTERVENTIONS

Oral treatment with either 750 mg amoxicillin or placebo three times daily for 100 days.

MAIN OUTCOME MEASURES

Quality-adjusted life years (QALYs) by EuroQoL-5D over 12 months and costs for healthcare and productivity loss measured in Euro (€1=NOK 10), in the intention-to-treat population. Cost-utility was expressed in incremental cost-effectiveness ratio (ICER).

RESULTS

Mean (SD) total cost was €21 046 (20 105) in the amoxicillin group and €19 076 (19 356) in the placebo group, mean difference €1970 (95% CI; -3835 to 7774). Cost per QALY gained was €24 625. In those with type I Modic changes, the amoxicillin group had higher healthcare consumption than the placebo group, resulting in €39 425 per QALY gained. Given these ICERs and a willingness-to-pay threshold of €27 500 (NOK 275 000), the probability of amoxicillin being cost-effective was 51%. Even when the willingness-to-pay threshold increased to €55 000, the probability of amoxicillin being cost-effective was never higher than 53%.

CONCLUSIONS

Amoxicillin treatment showed no evidence of being cost-effective for people with chronic LBP and Modic changes during 1-year follow-up.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT02323412.

Association of Modic change types and their short tau inversion recovery signals with clinical characteristics- a cross sectional study of chronic low back pain patients in the AIM-study

BACKGROUND

Modic Changes (MCs, magnetic resonance imaging (MRI) signal changes in the vertebral bone marrow extending from the vertebral endplate) may represent a subgroup of nonspecific chronic low back pain that could benefit from a specific management. The primary aim was to compare clinical characteristics between patients with type 1 versus type 2 MCs. The secondary aim was to explore associations between clinical characteristics and MC related short tau inversion recovery (STIR) signals.

METHODS

This cross-sectional study used baseline data prospectively collected between 2015 and 2017 on the 180 patients included in the AIM-study (Antibiotics In Modic changes), a randomized controlled trial in a Norwegian hospital out-patient setting of patients with chronic low back pain, a lumbar disc herniation within the last 2 years, low back pain intensity score ≥ 5 (on a 0-10 scale) and current type 1 or type 2 MCs at the previously herniated lumbar disc level. We used prespecified clinical characteristics including self-report measures, physiologic measures and functional measures from clinical history and examination. The diagnostic accuracy of various clinical characteristics to discriminate between patients with type 1 MCs (with or without additional type 2 MCs) and patents with type 2 MCs only (not type 1) were assessed by calculating the area under the receiver-operating curve. We assessed the correlations of clinical characteristics with details of MC related STIR signal increase.

RESULTS

No clinical characteristic differed between patients with type 1 (n = 118) versus type 2 (but not type 1) (n = 62) MCs. The clinical characteristics showed no/minor differences or no/weak correlations with MC related STIR signal increase. Patients with a positive Springing test (at any lumbar level) had slightly less volume of STIR signal increase than those with a negative test (mean difference 1.3 on a 0-48 scale, 95% CI 0.3 to 2.3).

CONCLUSION

Clinical characteristics were similar for patients with type 1 MCs and patients with type 2 MCs, and showed no clinically relevant correlations with MC related STIR signal increase.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02323412, First registered 23 December 2014.

Association between vitamin D and fatigue in patients with rheumatoid arthritis: a cross-sectional study

OBJECTIVES

In rheumatoid arthritis (RA), fatigue is an important complaint with a significant impact on quality of life. Vitamin D has modulatory effects on cells of the immune system and may potentially affect RA disease activity and thereby RA-related fatigue. The purpose of this study was to explore associations between fatigue and vitamin D status in patients with RA.

DESIGN

Hypothesis-generating cross-sectional study.

SETTING

Scheduled follow-up visits at a hospital-based general rheumatology clinic.

PARTICIPANTS

Patients (n=169) with established RA.

PRIMARY OUTCOME MEASURES AND ANLYSES

Fatigue, assessed by the Chalder fatigue questionnaire, and serum concentrations of 25-hydroxyvitamin D (25(OH)D), assessed by liquid chromatography-tandem mass spectrometry. Associations were analysed by correlation, and multivariate linear regression with adjustments for age, sex, body mass index, RA disease activity as measured by the Disease Activity Score 28-joint count C reactive protein (DAS28-CRP), psychological distress, pain and sleep. Fatigue was also compared across four groups based on the levels of serum 25(OH)D with cut points at 30, 50 and 75 nmol/L using one-way analysis of variance.

RESULTS

Two-thirds of the patients (116/169, 69%) were classified with low RA disease activity, that is, a DAS28-CRP score below 3.2. Their mean (SD) serum 25(OH)D concentration was 56.3 (21.2) nmol/L, with 77 (45.6%) having values below 50 nmol/L and 12 patients (7.1%) below 30 nmol/L. The correlation between fatigue and serum concentrations of 25(OH)D was weak and not statistically significant, r = -0.14 (95% CI: -0.29 to 0.03, p=0.08). In the multivariate model, fatigue was significantly associated with RA disease activity, psychological distress and pain, but not with serum 25(OH)D. Fatigue did not differ across groups with varying levels of serum 25(OH)D.

CONCLUSION

This cross-sectional study found no evidence of association between vitamin D and fatigue in patients with RA.

New insight to the characteristics and clinical course of clusters of patients with imaging confirmed disc-related sciatica

BACKGROUND

Referral to secondary care is common for a considerable proportion of patients with persistent sciatica symptoms. It is unclear if information from clinical assessment can further identify distinct subgroups of disc-related sciatica, with perhaps different clinical courses.

AIMS

This study aims to identify and describe clusters of imaging confirmed disc-related sciatica patients using latent class analysis, and compare their clinical course.

METHODS

The study population were 466 patients with disc-related sciatica. Variables from clinical assessment were included in the analysis. Characteristics of the identified clusters were described and their clinical course over 2 years was compared.

RESULTS

A four-cluster solution was optimal. Cluster 1 (n = 110) had mild back and leg pain; cluster 2 (n = 59) had moderate back and leg pain; cluster 3 (n = 158) had mild back pain and severe leg pain; cluster 4 (n = 139) had severe back and leg pain. Patients in cluster 4 had the most severe profile in terms of disability, distress and comorbidity and the lowest reported global change and the smallest proportion of patients with a successful outcome at 2 years. Of the 135 patients who underwent surgery, 42% and 41% were in clusters 3 and 4, respectively.

CONCLUSIONS

Using a strict diagnosis of sciatica, this work identified four clusters of patients primarily differentiated by back and leg pain severity. Patients with severe back and leg pain had the most severe profile at baseline and follow-up irrespective of intervention. This simple classification system may be useful when considering prognosis and management with sciatica patients.

SIGNIFICANCE

Using data from a large observational prospective study, this work identifies four distinct clusters of patients with imaging confirmed disc-related sciatica. This classification could be used when considering prognosis and management with sciatica patients at their initial consultation.

Efficacy of antibiotic treatment in patients with chronic low back pain and Modic changes (the AIM study): double blind, randomised, placebo controlled, multicentre trial

OBJECTIVE

To assess the efficacy of three months of antibiotic treatment compared with placebo in patients with chronic low back pain, previous disc herniation, and vertebral endplate changes (Modic changes).

DESIGN

Double blind, parallel group, placebo controlled, multicentre trial.

SETTING

Hospital outpatient clinics at six hospitals in Norway.

PARTICIPANTS

180 patients with chronic low back pain, previous disc herniation, and type 1 (n=118) or type 2 (n=62) Modic changes enrolled from June 2015 to September 2017.

INTERVENTIONS

Patients were randomised to three months of oral treatment with either 750 mg amoxicillin or placebo three times daily. The allocation sequence was concealed by using a computer generated number on the prescription.

MAIN OUTCOME MEASURES

The primary outcome was the Roland-Morris Disability Questionnaire (RMDQ) score (range 0-24) at one year follow-up in the intention to treat population. The minimal clinically important between group difference in mean RMDQ score was predefined as 4.

RESULTS

In the primary analysis of the total cohort at one year, the difference in the mean RMDQ score between the amoxicillin group and the placebo group was -1.6 (95% confidence interval -3.1 to 0.0, P=0.04). In the secondary analysis, the difference in the mean RMDQ score between the groups was -2.3 (-4.2 to-0.4, P=0.02) for patients with type 1 Modic changes and -0.1 (-2.7 to 2.6, P=0.95) for patients with type 2 Modic changes. Fifty patients (56%) in the amoxicillin group experienced at least one drug related adverse event compared with 31 (34%) in the placebo group.

CONCLUSIONS

In this study on patients with chronic low back pain and Modic changes at the level of a previous disc herniation, three months of treatment with amoxicillin did not provide a clinically important benefit compared with placebo. Secondary analyses and sensitivity analyses supported this finding. Therefore, our results do not support the use of antibiotic treatment for chronic low back pain and Modic changes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02323412.

Up-regulation of circulating microRNA-17 is associated with lumbar radicular pain following disc herniation

Background

Previous studies suggest that regulatory microRNAs (miRs) may modulate neuro-inflammatory processes. The purpose of the present study was to examine the role of miR-17 following intervertebral disc herniation.

Methods

In a cohort of 97 patients with leg pain and disc herniation verified on MRI, we investigated the association between circulating miR-17 and leg pain intensity. A rat model was used to examine possible changes in miR-17 expression in nucleus pulposus (NP) associated with leak of NP tissue out of the herniated disc. The functional role of miR-17 was addressed by transfection of miR-17 into THP-1 cells (human monocyte cell line).

Results

An association between the level of miR-17 in serum and the intensity of lumbar radicular pain was shown. Up-regulation of miR-17 in the rat NP tissue when applied onto spinal nerve roots and increased release of TNF following transfection of miR-17 into THP-1 cells were also observed. Hence, our data suggest that miR-17 may be involved in the pathophysiology underlying lumbar radicular pain after disc herniation.

Conclusions

We conclude that miR-17 may be associated with the intensity of lumbar radicular pain after disc herniation, possibly through a TNF-driven pro-inflammatory mechanism.

Electronic supplementary material

The online version of this article (10.1186/s13075-019-1967-y) contains supplementary material, which is available to authorized users.

Lumbar spine surgery across 15 years: trends, complications and reoperations in a longitudinal observational study from Norway

BACKGROUND

Studies from different Western countries have reported a rapid increase in spinal surgery rates, an increase that exceeds by far the growing incidence rates of spinal disorders in the general population. There are few studies covering all lumbar spine surgery and no previous studies from Norway.

OBJECTIVES

The purpose of this study was to investigate trends in all lumbar spine surgery in Norway over 15 years, including length of hospital stay, and rates of complications and reoperations.

DESIGN

A longitudinal observational study over 15 years using hospital patient administrative data and sociodemographic data from the National Registry in Norway.

SETTING AND PARTICIPANTS

Patients aged ≥18 years discharged from Norwegian public hospitals between 1999 and 2013.

OUTCOME MEASURES

Annual rates of simple (microsurgical discectomy, decompression) and complex surgical procedures (fusion, disc prosthesis) in the lumbar spine.

RESULTS

The rate of lumbar spine surgery increased by 54%, from 78 (95% CI (75 to 80)) to 120 (107 to 113) per 100 000, from 1999 to 2013. More men had simple surgery whereas more women had complex surgery. Among elderly people over 75 years, lumbar surgery increased by a factor of five during the 15-year period. The rates of complications were low, but increased from 0.7% in 1999 to 2.4% in 2013.

CONCLUSIONS

There was a substantial increase in lumbar spine surgery in Norway from 1999 to 2013, similar to trends in other Western world countries. The rise in lumbar surgery among elderly people represents a significant workload and challenge for health services, given our aging population.

Complications, reoperations, readmissions, and length of hospital stay in 34 639 surgical cases of lumbar disc herniation

Aims

The aims of this study were to determine the rates of surgical complications, reoperations, and readmissions following herniated lumbar disc surgery, and to investigate the impact of sociodemographic factors and comorbidity on the rate of such unfavourable events.

Patients and Methods

This was a longitudinal observation study. Data from herniated lumbar disc operations were retrieved from a large medical database using a combination of procedure and diagnosis codes from all public hospitals in Norway from 1999 to 2013. The impact of age, gender, geographical affiliation, education, civil status, income, and comorbidity on unfavourable events were analyzed by logistic regression.

Results

Of 34 639 operations, 2.7% (95% confidence interval (CI) 2.6 to 2.9) had a surgical complication, 2.1% (95% CI 2.0 to 2.3) had repeat surgery within 90 days, 2.4% (95% CI 2.2 to 2.5) had a non-surgical readmission within 90 days, and 6.7% (95% CI 6.4 to 6.9) experienced at least one of these unfavourable events. Unfavourable events were found to be associated with advanced age and comorbidity.

Conclusion

The results suggest that surgical complications are less frequent than previously suggested. There are limited associations between sociodemographic patient characteristics and unfavourable events. Cite this article: Bone Joint J 2019;101-B:470–477.

Antibiotic treatment In patients with chronic low back pain and Modic changes (the AIM study): study protocol for a randomised controlled trial

Background

A previous randomised controlled trial (RCT) of patients with chronic low back pain (LBP) and vertebral bone marrow (Modic) changes (MCs) on magnetic resonance imaging (MRI), reported that a 3-month, high-dose course of antibiotics had a better effect than placebo at 12 months’ follow-up. The present study examines the effects of antibiotic treatment in chronic LBP patients with MCs at the level of a lumbar disc herniation, similar to the previous study. It also aims to assess the cost-effectiveness of the treatment, refine the MRI assessment of MCs, and further evaluate the impact of the treatment and the pathogenesis of MCs by studying genetic variability and the gene and protein expression of inflammatory biomarkers.

Methods/design

A double-blinded RCT is conducted at six hospitals in Norway, comparing orally administered amoxicillin 750 mg, or placebo three times a day, over a period of 100 days in patients with chronic LBP and type I or II MCs at the level of a MRI-confirmed lumbar disc herniation within the preceding 2 years. The inclusion will be stopped when at least 80 patients are included in each of the two MC type groups. In each MC type group, the study is designed to detect (β = 0.1, α = 0.05) a mean difference of 4 (standard deviation 5) in the Roland Morris Disability Questionnaire score between the two treatment groups (amoxicillin or placebo) at 1-year follow-up. The study includes cost-effectiveness measures. Blood samples are assessed for security measures and for possible inflammatory mediators and biomarkers at different time points. MCs are evaluated on MRI at baseline and after 12 months. A blinded intention-to-treat analysis of treatment effects will be performed in the total sample and in each MC type group.

Discussion

To ensure the appropriate use of antibiotic treatment, its effect in chronic LBP patients with MCs should be re-assessed. This study will investigate the effects and cost-effectiveness of amoxicillin in patients with chronic LBP and MCs at the level of a disc herniation. The study may also help to refine imaging and characterise the biomarkers of MCs.

Trial registration

ClinicalTrials.gov, ID: NCT02323412. Registered on 21 November 2014.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2306-8) contains supplementary material, which is available to authorized users.

Role of erosions typical of rheumatoid arthritis in the 2010 ACR/EULAR rheumatoid arthritis classification criteria: results from a very early arthritis cohort

OBJECTIVE

To determine how the European League Against Rheumatism (EULAR) definition of erosive disease (erosion criterion) contributes to the number of patients classified as rheumatoid arthritis (RA) according to the 2010 American College of Rheumatology/EULAR RA classification criteria (2010 RA criteria) in an early arthritis cohort.

METHODS

Patients from the observational study Norwegian Very Early Arthritis Clinic with joint swelling ≤16 weeks, a clinical diagnosis of RA or undifferentiated arthritis, and radiographs of hands and feet were included. Erosive disease was defined according to the EULAR definition accompanying the 2010 RA criteria. We calculated the additional number of patients being classified as RA based on the erosion criteria at baseline and during follow-up.

RESULTS

Of the 289 included patients, 120 (41.5%) fulfilled the 2010 RA criteria, whereas 15 (5.2%) fulfilled only the erosion criterion at baseline. 118 patients had radiographic follow-up at 2 years, of whom 6.8% fulfilled the 2010 RA criteria and only one patient fulfilled solely the erosion criterion during follow-up.

CONCLUSION

Few patients with early arthritis were classified as RA based on solely the erosion criteria, and of those who did almost all did so at baseline.

Disease Characteristics and Rheumatoid Arthritis Development in Patients with Early Undifferentiated Arthritis: A 2-year Followup Study

OBJECTIVE

To examine the 2-year disease course in patients with undifferentiated arthritis (UA) focusing on fulfillment of the 2010 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) rheumatoid arthritis (RA) classification criteria.

METHODS

Data were provided by the Norwegian Very Early Arthritis Clinic study, which included patients presenting with ≥ 1 swollen joint of ≤ 16 weeks' duration. UA was defined as patients not fulfilling the 2010 ACR/EULAR RA criteria and who did not have a clinical diagnosis other than RA at baseline. The main outcome was fulfillment of the 2010 RA criteria. Secondary outcomes were disease-modifying antirheumatic drug (DMARD) use, resolution of synovitis without use of DMARD during followup, and final clinical diagnosis.

RESULTS

We included 477 patients with UA of whom 47 fulfilled the 2010 ACR/EULAR RA criteria during followup (UA-RA) and 430 did not (UA-non-RA). Of the UA-RA patients, 70% fulfilled the criteria within the first 6 months. UA-RA patients were older, more often positive for rheumatoid factor and anticitrullinated protein antibodies, female, and ever smokers, and they more often presented with polyarticular arthritis, small joint involvement, and a swollen shoulder joint. During followup, 53% of UA-RA patients vs 13% of UA-non-RA patients used DMARD (p < 0.001). Overall, 71% of patients with UA achieved absence of clinical synovitis at final followup without use of DMARD. The most frequent final clinical diagnosis was UA (61%).

CONCLUSION

Only 9.8% of patients with UA fulfilled the 2010 RA criteria during 2-year followup. Small joint involvement and swollen shoulder joint were among the factors associated with RA development. In two-thirds of patients with UA, the arthritis resolved without use of DMARD.

Pain-related fear and functional recovery in sciatica: results from a 2-year observational study

OBJECTIVES

The purpose of this study was to explore the associations between pain-related fear, pain disability, and self-perceived recovery among patients with sciatica and disk herniation followed up for 2 years.

PATIENTS AND METHODS

Pain-related fear was measured by the Tampa Scale for Kinesiophobia (TSK) and the Fear-Avoidance Beliefs Questionnaire-Physical Activity (FABQ-PA) subscale. Disability was measured by the Maine-Seattle Back Questionnaire. At 2 years, patients reported their sciatica/back problem on a global change scale ranging from completely gone to much worse. No specific interventions regarding pain-related fear were provided.

RESULTS

Complete data were obtained for 372 patients. During follow-up, most patients improved. In those who at 2 years were fully recovered (n=66), pain-related fear decreased substantially. In those who did not improve (n=50), pain-related fear remained high. Baseline levels of pain-related fear did not differ significantly between those who were fully recovered and the rest of the cohort. In the total cohort, the correlation coefficients between the 0-2-year change in disability and the changes in the TSK and the FABQ-PA were 0.33 and 0.38, respectively. In the adjusted regression models, the 0-2-year change in pain-related disability explained 15% of the variance in the change in both questionnaires.

CONCLUSION

Pain-related fear decreased substantially in patients who recovered from sciatica and remained high in those who did not improve. Generally, the TSK and the FABQ-PA yielded similar results. To our knowledge, this is the first study that has assessed pain-related fear in patients who recover from sciatica.

Subjective health complaints in patients with lumbar radicular pain and disc herniation are associated with a sex - OPRM1 A118G polymorphism interaction: a prospective 1-year observational study

Background

Earlier observations show that development of persistent pain may be associated with the genetic variability in the gene encoding for the μ-opioid receptor 1, the OPRM1 A118G (rs1799971). The aim of this study was to investigate the association between OPRM1 genotype and subjective health complaints in patients with radicular pain and disc herniation.

Methods

A prospective, 1-year observational study was conducted at a hospital back clinic, including 118 Caucasian patients with lumbar radicular pain and MRI confirmed disc herniation. Single nucleotide polymorphism genotyping regarding the OPRM1 A118G was performed. The data of individuals with AA versus AG or GG were analysed separately by linear mixed models. The Subjective Health Complaints Inventory (0-81) including 27 common complaints experienced the previous month on a scale from not at all (0) to severe (3) was used as outcome. Pain, prior duration of leg pain, age, smoking status, and lumbar disc surgery were considered as covariates.

Results

In total 23 of 118 patients were carriers of the OPRM1 G-allele. All patients except female carriers of the G-allele reported a decrease in pain from baseline to 1 year. Female carriers of the G-allele reported significantly higher subjective health complaints score during the study time span than male carriers of the G-allele when controlling for pain and pain duration.

Conclusion

The present data indicate that, when controlling for pain intensity and duration, subjective health complaints are associated with a sex - OPRM1 A118G polymorphism interaction in patients with radicular pain.

Patients' ratings of global perceived change during 2 years were strongly influenced by the current health status

OBJECTIVES

To investigate the longitudinal validity of patients' ratings of global perceived change (GPC) and to assess the implications of using the GPC as the anchor to determine the minimal important change (MIC).

STUDY DESIGN AND SETTING

Secondary analysis of data from a multicenter study including 380 patients with disc-related sciatica with follow-ups at 3, 6, 12, and 24 months. The GPC scale ranged from much worse to completely gone. Five patient-reported outcome measures were used. An MIC was defined as the mean change score in the actual outcome measure for patients reporting being better. The influence of patients' current state and baseline scores on the GPC was analyzed by multivariate linear regression. Differences in the magnitude of the MIC between the 3- and 24-month recall periods were analyzed by hierarchical linear models.

RESULTS

Across all recall periods and outcome measures, the GPC was strongly influenced by the patient's state at the time of asking. In four of five outcome measures, the magnitude of the MIC increased when recall increased from 3 to 24 months.

CONCLUSION

Caution is needed when using the GPC to determine the MIC of patient-reported outcome measures in patients with chronic conditions.

Prognostic factors for return to work in patients with sciatica

BACKGROUND CONTEXT

Little is known about the prognostic factors for work-related outcomes of sciatica caused by disc herniation.

PURPOSE

To identify the prognostic factors for return to work (RTW) during a 2-year follow-up among sciatica patients referred to secondary care.

STUDY DESIGN/SETTING

Multicenter prospective cohort study including 466 patients. Administrative data from the National Sickness Benefit Register were accessed for 227 patients.

PATIENT SAMPLE

Two samples were used. Sample A comprised patients who at the time of inclusion in the cohort reported being on partial sick leave or complete sick leave or were undergoing rehabilitation because of back pain/sciatica. Sample B comprised patients who, according to the sickness benefit register, at the time of inclusion received sickness benefits or rehabilitation allowances because of back pain/sciatica.

OUTCOME MEASURES

In Sample A, the outcome was self-reported return to full-time work at the 2-year follow-up. In Sample B, the outcome was time to first sustained RTW, defined as the first period of more than 60 days without receiving benefits from the register.

METHODS

Significant baseline predictors of self-reported RTW at 2 years (Analysis A) were identified by multivariate logistic regression. Significant predictors of time to sustained RTW (Analysis B) were identified by multivariate Cox proportional hazard modeling. Both analyses included adjustment for age and sex. To assess the effect of surgery on the probability of RTW, analyses similar to A and B were performed, including the variable surgery (yes/no).

RESULTS

One-fourth of the patients were still out of work at the 2-year follow-up. In Sample A (n=237), younger age, better general health, lower baseline sciatica bothersomeness, less fear-avoidance work, and a negative straight-leg-raising test result were significantly associated with a higher probability of RTW at the 2-year follow-up. Surgery was not significantly associated with the outcome. In Sample B (n=125), history of sciatica, duration of the current sciatica episode more than 3 months, greater sciatica bothersomeness, fear-avoidance work, and back pain were significantly associated with a longer time to sustained RTW. Surgery was significantly negatively associated with time to sustained RTW both in univariate (hazard ratio [HR] 0.60; 95% confidence interval [CI] 0.39, 0.93; p=.02) and in multivariate (HR 0.49; 95% CI 0.31, 0.79; p=.003) analyses.

CONCLUSIONS

The baseline factors associated with RTW identified in multivariate analysis were age, general health, history of sciatica, duration of the current episode, baseline sciatica bothersomeness, fear-avoidance work, back pain, and the straight-leg-raising test result. Surgical treatment was associated with slower RTW, but surgical patients were more severely affected than patients treated without surgery; so, this finding should be interpreted with caution.

The prognosis of self-reported paresthesia and weakness in disc-related sciatica

PURPOSE

To explore how patients with sciatica rate the 'bothersomeness' of paresthesia (tingling and numbness) and weakness as compared with leg pain during 2 years of follow-up.

METHODS

Observational cohort study including 380 patients with sciatica and lumbar disc herniation referred to secondary care. Using the Sciatica Bothersomeness Index paresthesia, weakness and leg pain were rated on a scale from 0 to 6. A symptom score of 4-6 was defined as bothersome.

RESULTS

Along with leg pain, the bothersomeness of paresthesia and weakness both improved during follow-up. Those who received surgery (n = 121) reported larger improvements in both symptoms than did those who were treated without surgery. At 2 years, 18.2% of the patients reported bothersome paresthesia, 16.6% reported bothersome leg pain, and 11.5% reported bothersome weakness. Among patients with no or little leg pain, 6.7% reported bothersome paresthesia and 5.1% bothersome weakness.

CONCLUSION

During 2 years of follow-up, patients considered paresthesia more bothersome than weakness. At 2 years, the percentage of patients who reported bothersome paresthesia was similar to the percentage who reported bothersome leg pain. Based on patients' self-report, paresthesia and weakness are relevant aspects of disc-related sciatica.

Prognostic factors for non-success in patients with sciatica and disc herniation

BACKGROUND

Few studies have investigated prognostic factors for patients with sciatica, especially for patients treated without surgery. The aim of this study was to identify factors associated with non-success after 1 and 2 years of follow-up and to test the prognostic value of surgical treatment for sciatica.

METHODS

The study was a prospective multicentre observational study including 466 patients with sciatica and lumbar disc herniation. Potential prognostic factors were sociodemographic characteristics, back pain history, kinesiophobia, emotional distress, pain, comorbidity and clinical examination findings. Study participation did not alter treatment considerations for the patients in the clinics. Patients reported on the questionnaires if surgery of the disc herniation had been performed. Uni- and multivariate logistic regression analyses were used to evaluate factors associated with non-success, defined as Maine-Seattle Back Questionnaire score of ≥5 (0-12) (primary outcome) and Sciatica Bothersomeness Index ≥7 (0-24) (secondary outcome).

RESULTS

Rates of non-success were at 1 and 2 years 44% and 39% for the main outcome and 47% and 42% for the secondary outcome. Approximately 1/3 of the patients were treated surgically. For the main outcome variable, in the final multivariate model non-success at 1 year was significantly associated with being male (OR 1.70 [95% CI; 1.06 - 2.73]), smoker (2.06 [1.31 - 3.25]), more back pain (1.0 [1.01 - 1.02]), more comorbid subjective health complaints (1.09 [1.03 - 1.15]), reduced tendon reflex (1.62 [1.03 - 2.56]), and not treated surgically (2.97 [1.75 - 5.04]). Further, factors significantly associated with non-success at 2 years were duration of back problems >; 1 year (1.92 [1.11 - 3.32]), duration of sciatica >; 3 months (2.30 [1.40 - 3.80]), more comorbid subjective health complaints (1.10 [1.03 - 1.17]) and kinesiophobia (1.04 [1.00 - 1.08]). For the secondary outcome variable, in the final multivariate model, more comorbid subjective health complaints, more back pain, muscular weakness at clinical examination, and not treated surgically, were independent prognostic factors for non-success at both 1 and 2 years.

CONCLUSIONS

The results indicate that the prognosis for sciatica referred to secondary care is not that good and only slightly better after surgery and that comorbidity should be assessed in patients with sciatica. This calls for a broader assessment of patients with sciatica than the traditional clinical assessment in which mainly the physical symptoms and signs are investigated.

Poor agreement found between self-report and a public registry on duration of sickness absence

OBJECTIVE

To investigate the agreement between self-report and a public registry regarding the occurrence and duration of sickness absence (SA) in patients with sciatica.

STUDY DESIGN AND SETTING

Observational 2-year longitudinal study including 227 patients. Self-report SA data were obtained by postal questionnaires covering recall periods of 3, 6, and 12 months and compared with data from the Norwegian National Sickness Benefit Register.

RESULTS

The percent agreement on the occurrence of SA between self-report and registry was above 85% for all three recall periods. The patients overestimated the duration of their SA by 2.4 (95% confidence interval, 1.1-3.7) weeks for the 3-month recall period. The 95% limits of agreement were generally wide, varying from -12.5 to 17.3 weeks for the 3-month recall period to -38.8 to 37.2 weeks for the 12-month period. For the 3-, 6-, and 12-month recall periods, 48.1%, 29.8%, and 27.3% of the patients reported an SA duration that differed by ≤1 week from that recorded in the registry.

CONCLUSION

Mainly because of low precision, the agreement on the duration of SA was poor for all three recall periods. The agreement between self-report and registry regarding the occurrence of SA was good.